<?php
$host = '127.0.0.1';
$port = '9505';
//创建tcp socket
$socket = socket_create(AF_INET, SOCK_STREAM, SOL_TCP);
socket_set_option($socket, SOL_SOCKET, SO_REUSEADDR, 1);
socket_bind($socket, 0, $port);
//监听端口
socket_listen($socket);
//连接的client socket 列表
$clients = array($socket);
//设置一个死循环,用来监听连接 ,状态
while(true){ 
    $changed = $clients;
    socket_select($changed, NULL, NULL, 0, 10);
    //如果有新的连接
    if(in_array($socket, $changed)){ //接受并加入新的socket连接
        $socket_new = socket_accept($socket);
        $clients[] = $socket_new;
        //通过socket获取数据执行handshake
        $header = socket_read($socket_new, 1024);
        perform_handshaking($header, $socket_new, $host, $port);
        //获取client ip 编码json数据,并发送通知
        socket_getpeername($socket_new, $ip);
        $response = mask(json_encode(array('type' => 'system', 'message' => $ip . ' connected')));
        send_message($response);
        $found_socket = array_search($socket, $changed);
        unset($changed[$found_socket]);
    }else{
        //轮询 每个client socket 连接
        foreach($changed as $changed_socket){ //如果有client数据发送过来
            while(socket_recv($changed_socket, $buf, 1024, 0) >= 1){ //解码发送过来的数据
                $received_text = unmask($buf);
                $tst_msg       = json_decode($received_text);
                $user_name     = $tst_msg->name;
                $user_message  = $tst_msg->message;

                //把消息发送回所有连接的 client 上去
                $response_text = mask(json_encode(array( 'type'    => 'usermsg',
                    'name'    => $user_name,
                    'message' => $user_message
                )));
                send_message($response_text);
                break 2;
            } 
            //检查offline的client
            $buf = @socket_read($changed_socket, 1024, PHP_NORMAL_READ);
            if($buf === false){ $found_socket = array_search($changed_socket, $clients);
                socket_getpeername($changed_socket, $ip);
                unset($clients[$found_socket]);
                $response = mask(json_encode(array('type' => 'system', 'message' => $ip . ' disconnected')));
                send_message($response);
            } 
        } 
    }
    
} // 关闭监听的socket
socket_close($sock);

//发送消息的方法
function send_message($msg){ 
    global $clients;
    foreach($clients as $changed_socket){ 
        @socket_write($changed_socket, $msg, strlen($msg));
    } 
    return true;
} //解码数据

function unmask($text){ 
    echo 'kaishi:'.$text;
    $length = ord($text[1]) & 127;
    if($length == 126){ $masks = substr($text, 4, 4);
        $data  = substr($text, 8);
    }elseif($length == 127){ $masks = substr($text, 10, 4);
        $data  = substr($text, 14);
    }else{ 
        $masks = substr($text, 2, 4);
        $data  = substr($text, 6);
    } 
    $text = "";
    for($i = 0; $i < strlen($data); ++$i){ 
        $text .= $data[$i] ^ $masks[$i % 4];
    } 
    echo $text;
    return $text;
} //编码数据
function mask($text){ 
    $b1     = 0x80 | (0x1 & 0x0f);
    $length = strlen($text);
    if($length <= 125){ 
        $header = pack('CC', $b1, $length);
    }elseif($length > 125 && $length < 65536){ 
        $header = pack('CCn', $b1, 126, $length);
    }elseif($length >= 65536){ 
        $header = pack('CCNN', $b1, 127, $length);
    } return $header . $text;
} 

//握手的逻辑
function perform_handshaking($receved_header, $client_conn, $host, $port){ $headers = array();
    $lines   = preg_split("/\r\n/", $receved_header);
    foreach($lines as $line){ $line = chop($line);
        if(preg_match('/\A(\S+): (.*)\z/', $line, $matches)){ $headers[$matches[1]] = $matches[2];
        } } $secKey    = $headers['Sec-WebSocket-Key'];
    $secAccept = base64_encode(pack('H*', sha1($secKey . '258EAFA5-E914-47DA-95CA-C5AB0DC85B11')));
    $upgrade   = "HTTP/1.1 101 Web Socket Protocol Handshake\r\n" . "Upgrade: websocket\r\n" . "Connection: Upgrade\r\n" . "WebSocket-Origin: $host\r\n" . "WebSocket-Location: ws://$host:$port/demo/shout.php\r\n" . "Sec-WebSocket-Accept:$secAccept\r\n\r\n";
    socket_write($client_conn, $upgrade, strlen($upgrade));
}